While conventional automotive air conditioning provides cooling to the “front” portions of an individual on hot summer days, the back and seat portions of an individual driver or passenger receives little relief from such conventional general automotive interior cooling because of the lack of exposure of such areas of the body to the air conditioned environment. Thus, the provision of cooling to the seat and back areas of, for example, an automobile driver or passenger during hot weather has been the subject of much development.
U.S. Pat. No. 6,189,967 to Short issued Feb. 20, 2001 describes a portable air cooled seat cushion provided with a fan that produces an air stream directed to the interior of the portable cushion. The cushion has an air permeable outer covering on the front face thereof that permits air to flow out of the cushion against the legs and back of a user. A fan is located remote from the cushion and is connected to the cushion by a flexible hose to provide air circulation within the seat and back portions of the cushion. The interior of the cushion includes a relatively porous filler that provides air passages within the seat and back portions of the cushion. A preferred embodiment utilizes an existing such seat cushion that incorporates a series of wire coils as the relatively open porous filler that allows for “virtually unrestricted air flow through the seat and back portions of the cushion”. While such a device may provide a basic cooling structure, it possesses many shortcomings. Among these are the need to store and locate a remotely located fan/connecting hose assembly in the already crowded front seat of an automobile and the relatively poor air distribution provided by the wire coil structure in the cushion. In order to achieve appropriate air distribution in such a cushion an extremely high volume fan needs to be injected to assure that all of the circulating air is not disbursed through the cushion at or near the port of entry or very poor air distribution will be provided throughout the cushion.
U.S. Pat. No. 6,629,724 to Ekern et al. issued Oct. 7, 2003 describes a ventilated seat cushion assembly comprising an upper surface layer formed of a porous material, a lower surface layer and two inner layers. The first inner layer is formed of a non-porous material that faces the upper surface and is provided with ventilation holes for allowing air to flow though the upper surface layer. The second inner layer is porous and is positioned between to first inner layer and the lower surface layer. The inner porous layer is preferably a “spring-like” cushion having top and bottom netting and an interior consisting of rigidized threads extending between the top and bottom netting. An incorporated fan drives or sucks air through the second inner layer into or out of the ventilation holes provided in the first inner layer and hence through the upper surface layer. Thus, this device relies upon an array of “rigidized threads” to provide the porosity necessary to allow communication of cooling air from the fan to the upper surface layer. A tacky layer is used between the porous inner layer and the lower surface to inhibit relative movement between these elements. While such a device provides an alternative to that described by Short it also may not provide the longevity desired for such a device because of its reliance upon “rigidized threads” for the provision of a porous interior layer for the circulation of air within the device. Such an arrangement, while probably providing satisfactory initial service, will almost undoubtedly become less effective as the rigidized threads are repeatedly crushed by the weight of the user over time. Thus, it would be desirable to have a structure that would provide for an extended life for such a seat cooling device.